M: Mommy! Can I change my shirt? It's got some of Jaela's blood on it!
J: How did it get Jaela's blood on it?
M: Jaela has a bloody nose!
M: (matter-of-factly...) Because we were fighting and I punched her in the nose.
Oh. Of course. I guess that would do it!
I think maybe my little ladies have been reading too many adventure/detective stories...